Without limiting the scope of the invention, its background is described in connection with charge coupled device (CCD) image sensors, as an example. Essential to good low noise performance of a CCD image sensor is the charge detection amplifier which converts charge stored at an individual photo site into a signal of adequate magnitude for further processing.
The most popular charge detection concept in CCD sensors is based on a floating diffusion circuit. A typical prior art charge detection amplifier consists of a floating diffusion detection node and an amplifier circuit. See Hynecek, J., "Method of Making Top Buss Virtual Phase Frame Interline Transfer CCD Image Sensor", U.S. Pat. No. 5,151,380, issued Sep. 29, 1992. The charge detection node is a conventional gated floating diffusion structure typically used with virtual phase CCDs and has an externally driven reset gate.